Electrical circuits and various electrical devices may be susceptible to generating metastable output signals (e.g., an undefined, invalid, or mistimed output signal or one that requires an indeterminate amount of time to generate a valid output). For example, metastability issues may arise in mixed-signal systems (e.g., one or more integrated circuits) that include analog circuitry that interfaces with a digital circuit (e.g., a programmable logic device (PLD)) to form an analog-to-digital interface.
In general, for the above example, the PLD may be synchronized with the main system clock. However, the analog circuitry may not be synchronized. Consequently, metastability-induced erroneous operation may occur as the analog circuitry may provide output signals that change state randomly with respect to the main system clock of the PLD. The metastability issues may interfere with regular system operation and may lead to overall system failure in worst-case situations. As a result, there is a need for improved analog/digital interface techniques.